1. Field of the Invention
The present invention relates to winter climbing gear and/or equipment, and  particularly, to ice screws that are inserted or screwed into a body of ice for the purpose of providing a climber means whereby he/she may couple or secure a support structure, such as a carabiner, thereto, for support and security while climbing a snow/ice packed mountain. Even more particularly, the present invention relates to a flexing or breakaway crank handle attached to the hanger of an ice screw that functions to facilitate more efficient screwing of the ice screw into the body of ice, as well as to facilitate the repositioning of a carabiner, any ropes or additional carabiners attached in-line, slings, etc. or allow each to be repositioned, to a proper or correct load bearing position if the carabiner initially is improperly loaded.
2. Background of the Invention and Related Art
Mountain climbing, and particularly winter or alpine climbing, has evolved into a highly technical sport with climbers utilizing much more sophisticated equipment or gear to ascend a mountain of snow and ice. Included in the winter climber's gear are several ice screws having a hanger or hanger portion thereon, wherein the ice screws are inserted or screwed into a body of ice leaving the hanger portion exposed for the purpose of providing means to couple a carabiner thereto and to support the climber on the mountain or icy face.
Several different designs of ice screws exist in the market. As ice screws are required to be inserted several inches into the ice to provide adequate support for the climber, the advent of a cranking arm or crank handle has been introduced to facilitate the insertion and screwing of the threaded shaft into the ice. The climber grasps the cranking handle and uses it as leverage to create a greater amount of force used to drive the ice screw into the ice. Different types of cranking arms exist and are utilized on different types of ice screws, some of the most common being described below.
One of the problems associated with ice screws, and particularly ice screws utilizing a crank handle, is cross-loading. Cross-loading is defined as the situation when a carabiner is operational in a load sharing arrangement, but there is a component of force acting across the spine of the carabiner. In the case of an ice screw having a crank handle, this handle typically tends to protrude out from the hanger a substantial distance, enough to provide an obstruction to a carabiner, or to provide means by which the carabiner may get caught, thus causing the carabiner to be arranged in an abnormal, unsafe orientation or arrangement. If cross-loading occurs, the strength of the carabiner is reduced dramatically, thus increasing the potential for failure of the carabiner and overall risk to the climber. Cross-loading of a carabiner is a common problem in climbing, but even more so when there is a component on the device the carabiner is being coupled to that impedes the normal operation and movement of the carabiner, such as a crank handle.
As indicated, in the case of winter or alpine climbing, ice screws have been developed to comprise crank handles to make the task of screwing or driving the ice screw into a body of ice much easier and much more efficient by making the cranking process much easier for the climber. However, to be effective and to provide an efficient crank arm these crank handles must protrude a substantial distance from the hanger component of the ice screw. As a result, the carabiners coupled to the hanger have a tendency to get caught or hung up on the crank handles, thus contributing to the problem of cross-loading and the carabiner is at a fraction of its strength, unless it can free itself or is caused to disengage the crank handle. Several prior art designs have addressed the difficulties associated with screwing ice screws into a body of ice, as well as the problems associated with cross-loading of carabiners due to the addition of a crank handle.
Referring to FIGS. 1-A and 1-B, U.S. Pat. No. 5,782,442 to Kwak et al. discloses an ice screw having a hollow tubular shaft with external screw threads formed on the shaft to form a threaded screw 2 and a hanger 4 attached to threaded screw 2. Hanger 4 has an eye for clipping on a carabiner. A foldable crank handle 8 is pivotally attached to hanger 4 to pivot between a folded position (FIG. 1-A) and a crank position (FIG. 1-B). In the crank position, foldable crank handle 8 extends from hanger 8 for grasping to rotate and thus rotate the shaft. In the folded position, the handle folds into a recess 7 formed in hanger 4. In the crank position, hanger 4 serves as a lever arm or crank arm for handle 8. Although this design eliminates the problem of cross-loading because the crank handle is able to fold out of the way, there are several other problems inherent in this design. First, hanger 4 must be larger to accommodate a recessed portion that crank handle 8 may fold into. This increases not only the overall weight of the ice screw in a weight conscious sport, but also makes hanger 4 more bulky and cumbersome. Second, since crank handle 8 is manually actuated, the spring or biasing member contained within the crank handle cannot be too stiff. If it were too stiff, the handle would not fold easily, or worse yet, would require an additional tool to fold it into recess 7. As such, since it is desirable to manually fold crank handle 8, the spring must be comprise an appropriate spring constant and associated stiffness. This creates a significant problem when cranking crank handle 8. As the climber inserts the ice screw into the ice and begins cranking, the crank handle will have a tendency to fold or pivot at certain crank positions due to the force exerted on the crank handle by the climber and the lack of a sufficient spring constant to keep the crank handle from inadvertently folding during the cranking process.
With reference to FIG. 2, shown is another prior art ice screw comprising a crank handle 8. This crank handle, while possessive of good cranking characteristics, is extremely bulky and unnecessarily large and requires the climber to physically manipulate the crank handle to crank the ice screw and also to fold it out of the way once the ice screw is inserted. In addition, crank handle 8 tends to get caught on several items, including clothing, rope, and other climbing gear because of its size.
Accordingly, what is needed is an ice screw having a crank handle for facilitating cranking ease and efficiency and that does not allow undue folding during the cranking process, as well as a cranking handle that concurrently reduces or eliminates the problem of cross-loading.